Opinion on Windows 8 may be all over the map, but here’s one thing we all should be able to agree on: the more apps that take full advantage of the Windows 8 interface, the better shape the operating system will be in. What it needs, and hasn’t had, is a profusion of killer apps.

At yesterday’s DEMO Mobile conference in San Francisco, I saw one of the first third-party Windows 8 programs that got me excited: TouchMail. As its name indicates, it’s an e-mail client designed for touch input.

More important, though, it’s an e-mail client that feels like it was born to work well on Windows 8. For instance, instead of a conventional inbox, you get tiles which show incoming messages and provide a longer-than usual snippet of text. (They can be color-coded, so you can spot messages from your boss or your spouse.) You can zoom out to see more and more messages; if you go far enough, the tiles turn into icons representing the messages’ senders, and you can quickly slide back to a particular day, week or month.

TouchMail looks like it could be a super-efficient way to blast through vast quantities of mail; its creators say it’s designed for folks who get at least a hundred messages a day. It’s a little premature to judge it, though: the version which is live on the Windows Store is a teaser rather thank a working e-mail program. In fact, you can’t use it to get your own mail yet, only to view some sample messages.

At DEMO, TouchMail’s creators got questioned by a doubtful judge about why they chose to launch on Windows rather than other platforms. (I understood his reasoning, but I was still startled — even five years ago, I can’t imagine anyone thinking that Windows wasn’t the by far the most obvious operating system to launch a new product on.) It turns out that they do intend to bring their creation to other devices, beginning with the one I use most, the iPad.

I’m happy to hear that — but I’ll also be tickled if TouchMail turns out good enough that it helps sell a still-skeptical planet on the value of Windows 8.